Advances in molecular genetics have made it possible to select plants based on genetic markers linked to traits of interest, a process called marker-assisted selection (MAS). While breeding efforts to date have provided a number of useful corn lines and varieties with beneficial traits, there remains a need in the art for selection of varieties with further improved traits and methods for their production. In many cases, such efforts have been hampered by difficulties in identifying and using alleles conferring beneficial traits. These efforts can be confounded by the lack of definitive phenotypic assays, as well as other issues such as epistasis and polygenic or quantitative inheritance. In the absence of molecular tools such as MAS, it may not be practical to attempt to produce certain new genotypes of crop plants due to such challenges.